In an energy-assisted magnetic recording (EAMR) system, local heating is utilized to heat up a recording medium such that the coercivity of the recording medium can be reduced. With the coercivity of the heated location of the recording medium being temporarily reduced, an applied magnetic writing field can more easily direct the magnetization of the recording medium. In the EAMR system, magnetic recording heads (including writer and reader) and a light delivery system are operatively integrated together. The recording density is mainly controlled by the minimum thermal spot size in the recording medium that is produced by an optical near field transducer (NFT) at the excitation state (e.g., surface plasmon-resonance). The NFT is designed to reach a local surface plasmon (LSP) condition at a designated light wavelength.
In the related art, a typical EAMR head design includes a writer pole and a chimney (i.e., a heat sink) connecting the writer pole and an NFT located adjacent to an end of an optical waveguide core. The NFT is typically made of gold (Au) or an alloy of Au, and the NFT may have a disc shaped body (or other suitable shapes) and a pin (or peg) having one end connected with the disc shaped body and another end that is exposed at an air bearing surface (ABS) of the EAMR. A spacer is placed between the NFT and the waveguide core, and the spacer may be made of SiO2 or Al2O3. However, there are advantages for choosing SiO2 instead of Al2O3 as the material for the spacer and/or cladding materials. For example, Al2O3 has known erosion/corrosion problems and lower NFT media absorption efficiency than SiO2. However, when the NFT is made of gold or an alloy of gold, there are known adhesion issues at the interface between Au (or an alloy of Au) and SiO2. Therefore, it is desirable to provide a system for addressing the above described adhesion problem.